Mars Ancient Oceans
Could this have been Mars 3.5 billion years ago? Accumulating evidence from spacecraft like the Mars Reconniassance Orbiter shows signs of river networks on the surface. New research from the MRO laser altimeter, to be published in Nature Geoscience on June 13, shows that many river deltas were at exactly the same elevation 3.5 billion years in the past. This would indicate that the deltas all fed into one enormous ocean.
3.5 billion years is also the approximate age of carbonate globules found in meteortie ALH84001. These globules are one of four lines of evidence indicating Martian life from the metorite. This discovery from 1996 energized the new science of astrobiology. Recent work by Kathy Thomas-Keprta and colleagues at Johnson Space Center strengthens the case for ancient Martian life. This life could have thrived in an ancient ocean.
The "Faint Young Sun" hypothesis stated that the early Sun was 25% less luminous. Both Earth and Mars would have been frozen solid. The appearance of life would have been unlikely. Solar luminosity would continually increase (lower line) until Earth's oceans would boil. This astrophysical theory is not supported by evidence. Overwhelming evidence shows that both planets were warm enough for liquid water and life.
The Sun turns fuel to energy according to E=mc^2. If the speed of light c had increased at GM=tc^3 predicts, solar luminosity would be nearly constant (upper line). Earth would have conditions for life to evolve over billions of years. The fact that life exists to read this article is evidence that the speed of light has changed in precisely the amounts predicted.